Velomobile Frontal area

I finally have measured the frontal area of the new shape and the result has been good as the frontal area for this new shape is 0.36m2.

Calculating the CdA is now 0.36 x 0.21 (Cd) = 0.0756 CdA.
I can calculate using this excellent calculator power outputs and speeds for Veloci-velomobile. The graph below shows that for a modest 150W of power  a speed of  approx. 46 km/hr can be attained. I used 150W because this is what a untrained but fit cyclist could acheive for any length of time.

I also found that smoothing my final shape did not make any real difference to the Cd factor, at the most  it would have changed it by 0.1 so it is best to leave it as is. Now to build the models and then the real thing!

Rendering and Unfolding of the bodyshell

I am happy with the final shape and the Cd factor of this shape. Have unfolded it now to cut out to make 1/10th size model and then I will make a 1/4 size to sort out any small problems.

Aero tests continued

Last post I had a result that provided a cdA of 0.027. Unfortunately this result was wrong and after more testing I would have to put that result down to a glitch in the system.
Anyway I really liked the look of that particular shape which also allows more shoulder room for the rider. I ran the new tests after calibrating the software against a shape with a known Cd ( a sphere = 0.5). The new shape came back of a best of Cd=0.18 and with a slightly smaller frontal area of 0.44m2 with calculates to a CdA of 0.792 which is pretty good for a shape that can be produced using corflute/coroplast.

Veloci velomobile CdA=0.792

Veloci velomobile in virtual windtunnel

I am very happy with this shape now and the chassis design is going very well. I considered buying a KMX kart to use as a chassis but there were three things that I didn't like about these trikes...

1. Quite heavy at 19kg
2. Wheelbase not quite long enough
3. No suspension

KMX Karts are great value however and a fine product and would be suitable for a low cost velomobile. I will be building my own chassis this winter and hope to have Veloci-velo ready for Spring.